SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bac636b4d09265e39916e69146292935658a256bdbc4c9955cc65859e7d4a173' 
  AND token = 'rA35rtqOT6O60zoC2tcaUBCS6JWR31QJ0Vg6f56mLmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}